Spelling dictionaries, not game dictionaries
The lists are based on open spelling dictionaries and word collections. They are large and carefully maintained, and they contain real words in many forms: plurals, verb forms and variant spellings. They are not the official word lists of Scrabble, Wordfeud or any other game. Those lists are owned by the game makers and updated on their own schedule.
That has a practical consequence. A word in LetterUnmix is a real word according to its source. It is not a guarantee that your game accepts it. The reverse also happens: a game may accept a word that is missing here.
The English list
The English list combines two sources. The first is the English Speller Database, also known as SCOWL, in release 2026.02.25. It records for every word how common it is and in which dialect it belongs, which makes it possible to include American, British, Canadian and Australian spellings, and to leave out abbreviations, names and Roman numerals. The second is ENABLE, a public domain word list that many word games have used for years.
Because the database says how common each word is, the results can show which words are rare. In English, words that appear in neither the common part of the database nor the older lists are shown in light red. They are valid in some dictionaries, but they may not be accepted by the game you play.
The other languages
The Dutch list is based on the OpenTaal word list and spelling dictionary. The German list is based on igerman98, the dictionary used in many open-source programs. The French list comes from Dicollecte and the Spanish list from the open Spanish spelling dictionary. All of them are open sources. The exact versions and licences are on the sources and licences page.
These sources do not record how common a word is, so in those languages no word is marked as rare. Treat uncommon-looking results with the same care.
How the lists are cleaned
Before use, every list is processed in the same way. Only words made of letters are kept, so no hyphens, apostrophes, digits or spaces. Words must be between two and fifteen letters, which is the size of a board. Words without a vowel, such as abbreviations, are removed, apart from a short list of real exceptions. Capital letters and accents are normalised so that the search works the same however you type.
A few language-specific choices follow from this. In German the letters ä, ö and ü are kept and ß is written as ss. In Spanish the letter ñ is kept, while ch and ll count as two letters. In French and Dutch accents are removed, so a word like café is searched as cafe.
Updating and corrections
Language changes, and dictionaries are updated at their own pace. The lists on this site are renewed when a newer version of a source becomes available. If you find a mistake, tell us through the contact form.